Version 1.5.5 released

Version 1.5.5 changes

Security

If per_listener_settings is set to true, then the acl_file setting was
ignored for the "default listener" only. This has been fixed. This does not
affect any listeners defined with the listener option. Closes #1073.
This is now tracked as CVE-2018-20145.

Broker

Add socket_domain option to allow listeners to disable IPv6 support.
This is required to work around a problem in libwebsockets that means
sockets only listen on IPv6 by default if IPv6 support is compiled in.
Closes #1004.

When using ADNS, don't ask for all network protocols when connecting,
because this can lead to confusing "Protocol not supported" errors if the
network is down. Closes #1062.

Fix outgoing retained messages not being sent by bridges on initial
connection. Closes #1040.

Don't reload auth_opt_ options on reload, to match the behaviour of the
other plugin options. Closes #1068.

Print message on error when installing/uninstalling as a Windows service.